NCEA Level 1 Physics (90182) 2008 — page 1 of 3
Assessment Schedule – 2008
Demonstrate understanding of wave and light behaviour (90182)
Evidence StatementNote: Minor computational errors will not be penalised. A wrong answer will be accepted as correct provided there is sufficient evidence that the mistake is not due to a lack of understanding. Such evidence includes:
• the last written step before the answer is given has no unexpanded brackets or terms and does not require rearranging.
• the power of any number that is multiplied by a power of 10 is correct.
Q Evidence Achievement Achievement
with Merit Achievement with Excellence
ONE (a)
1 Correct ray diagram and image.
Arrows not required.
(b) Cellphone is opaque / does not let light pass through it.
Light passes though area round the phone and falls on the floor to create a dark shadow.
1 Either statement is given.
1 Both statements are given.
(c) T= 1
f = 1
1750=5.71!10–4 s
2 Correct answer using 1.75 kHz ( = 0.57 s)
2 Correct working and answer.
(d) != v f = 330
1750=0.188 m = 0.19 m
2 Correct working but incorrect answer using f as 1.75 kHz (= 188.5 m)
2 Correct working and answer.
(e) The speaker / speaker cone vibrates and the air particles near the cone vibrate at the same frequency. This sets up compressions and rarefactions in the air, which carry the sound energy / wave through the air to Jordan’s ear.
1 The speaker sets up vibrations in air, causing sound waves.
1 The speaker sets up vibrations in air. The air particles transmit these vibrations to Jordan’s ear.
1 Explanation shows a clear understanding of the phenomenon.
Compressions / rarefractions.
(f)
voptic fibre = =3.0!108
1.55 =1.935!108 ms–1 t= d
voptic = 100!103
1.935!108 =5.2!10"4 s
2 Correct answer for v in optic fibre
2 Correct process and given the answer for time using
d = 100 km (= 5.2 × 10–7 s)
2 Correct working and answer.
f
l
o
o
r
NCEA Level 1 Physics (90182) 2008 — page 2 of 3
TWO (a)
λ = 0.30 × 2 = 0.60 m
v = f λ = 2.5 ! 0.60 = 1.5 m s–1
2 Correct answer for λ OR correct working for v using λ as 0.30 m.
v = 0.75 ms–1
2 Correct working and answer.
(b) 1. Both are longitudinal waves
OR In both, the particles vibrate parallel to the direction of wave transmission.
2. Both are mechanical waves.
1 Either statement is given.
(c) Amplitude = 5.6/2 = 2.8 2 Correct answer.
(d) The particles vibrate at 90° to the direction of wave motion.
1. Correct description.
(e) v=d
t = 4500
1.5!10"5 =3.0!108 m s–1
! =4500
5 =900 m f = v
! =3.0"108
900 =333333.33 Hz = 333 kHz
OR
f = number/second
= 5
1.5!10–5 = 333 k Hz
2 Correct answer for v or λ.
2 Correct answer for v and λ OR
Correct answer in Hertz.
2 Correct working and answer in kilohertz.
(f) 1. As the air is slowly removed by the vacuum pump, the sound fades away and when all air is removed, very little / no sound is heard.
2. Sound requires a medium to travel. When air is removed, less and less particles are present until no medium is available for sound to travel.
1 Mentions sound disappears.
1 Statement 1 is given.
AND
needs medium.
1 Correct description and
explanation.
THREE (a)
1 All rays are reflected in parallel, but angles of reflection and incidence are not shown as equal.
1 All rays are correctly reflected in parallel, shown by drawing normal.
(b) 90 – 52 = 38° 2 Correct answer.
NCEA Level 1 Physics (90182) 2008 — page 3 of 3
(c) 1 Correct bending
of ray at either boundary is shown OR
both but no normals.
1 Correct bending of ray shown at both
boundaries.
(d) nair
njuice = vjuice vair !1.00
1.43= vjuice 3.00"108 v juice = 2.097 × 108 m s–1
njuice nglass = vglass
vjuice !1.43
1.54= vglass 2.097"108 v glass = 1.95 × 108 m s–1
2 Correct substitution for either of the steps.
OR Used
3.00!108 1.54 to get the correct answer but no explanation given to why it is used.
2 Correct process, but failed to get the correct answer due to incorrect mathematical process.
2 Correct working and answer. The working must be shown in two steps.
OR Used
3.00!108 1.54 to get the correct answer AND gives a reason for why it is used.
(e) 1 Shows an
understanding that light is reflected at the base to form an inverted image.
1 Correct drawing, but angles of incidence and reflection are almost correct.
1 Correct diagram to produce the inverted image.
Total opportunities criterion 1: 9 criterion 2: 8
criterion 1: 6 criterion 2: 6
criterion 1: 3 criterion 2: 3
Judgement Statement – 2008
Achievement Achievement with Merit Achievement with Excellence
5 × A1 3 × M1 + 3 × A1 2 × E1 + 2 × M1 + 3 × A1
4 × A2 4 × M2 + 2 × A2 2 × E1 + 2 × M2 + 3 × A2
